Revert "Make GrAtlasTextOp a non-legacy GrMeshDrawOp"

This reverts commit 434a58ab5fefcc1b86588c7fce898b1e5bd248ba.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Make GrAtlasTextOp a non-legacy GrMeshDrawOp
> 
> Change-Id: Ib9eaf149100b0ccecf1c18a755263f2579b8e6f6
> Reviewed-on: https://skia-review.googlesource.com/23482
> Reviewed-by: Jim Van Verth <jvanverth@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

TBR=jvanverth@google.com,bsalomon@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I7fd8503b4e0c297b2cfaf979545354aa58d1f989
Reviewed-on: https://skia-review.googlesource.com/23760
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
9 files changed